The tuning pins in a grand piano are installed in a laminated plank called a pinblock or wrestplank which is located beneath the large cast iron harp. Herein, it will be called a pinblock.
For more than a hundred years, some manufacturers of grand pianos have installed the pinblocks in the piano cases with wooden dowels, shims and glue along three sides and bottom of the pinblock, making it an integral part of the case.
Over a period of time the pinblocks will wear and otherwise deteriorate to a point where they will no longer securely hold the tuning pins and the pinblock will have to be replaced.
The known methods of removing the old blocks involve the use of hammers, chisels, saws of various sorts and electric routers. All of these methods are time consuming, uncontrollable and often result in residual damage to the finished parts of the cases.